When reading a netcdf grid we should add checks to determine if the global Conventions attribute exists and warn if it is not set or not containing COARDS or CF-1. This is because there resulting x,y ranges may not reflect the metadata if these have custom names. As an example, the grid discussed in message RE: Projection mismatch? pscoast and stereographic data returns with the wrong x,y info (basically set based on nx, ny instead).